Technical Field
The present invention relates to a solid-state imaging device, an image reading device, and an image forming apparatus.
Description of the Related Art
A solid-state image sensor represented by a complementary metal oxide semiconductor (CMOS) image sensor is used in various imaging devices such as video cameras, digital cameras, copy machines, and scanners.
Such a solid-state image sensor has a configuration where a plurality of photoelectric transducers generating electric charge in accordance with the amount of incident light is arranged in one line (linear image sensor) or a plurality of lines (area image sensor), and outputs an electric signal converted from the electric charge accumulated by each photoelectric transducer (pixel). In the process of generating electric charge and converting the electric charge to an electric signal, noise may occur due to variations among the pixels. Thus, a reference level (reference black level) of an electric signal output from the solid-state image sensor when there is no incident light is different in each line and at each time imaging is performed.